CVE-2021-22638
📋 TL;DR
CVE-2021-22638 is an out-of-bounds read vulnerability in Fatek FvDesigner software that allows arbitrary code execution when processing malicious project files. Attackers can craft special project files to exploit this vulnerability. Organizations using Fatek FvDesigner version 1.5.76 or earlier for industrial control system programming are affected.
💻 Affected Systems
- Fatek FvDesigner
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to execute arbitrary code with the same privileges as the FvDesigner application, potentially leading to industrial process disruption, data theft, or lateral movement within OT networks.
Likely Case
Local privilege escalation or remote code execution when users open malicious project files, potentially compromising the engineering workstation and adjacent industrial control systems.
If Mitigated
Limited impact if proper network segmentation, application whitelisting, and user privilege restrictions are implemented, though the vulnerability could still be exploited through social engineering.
🎯 Exploit Status
Exploitation requires user interaction to open a malicious project file. No public exploit code was available at the time of the advisory, but the vulnerability is well-documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.5.77 or later
Vendor Advisory: https://us-cert.cisa.gov/ics/advisories/icsa-21-056-02
Restart Required: Yes
Instructions:
1. Download FvDesigner version 1.5.77 or later from Fatek's official website. 2. Uninstall the vulnerable version. 3. Install the updated version. 4. Restart the system.
🔧 Temporary Workarounds
Restrict project file execution
windowsConfigure Windows to prevent execution of .fpj project files or restrict them to open only with updated FvDesigner versions
Use Windows Group Policy or application control solutions to restrict .fpj file execution
User awareness training
allTrain users to only open project files from trusted sources and verify file integrity
🧯 If You Can't Patch
- Implement strict network segmentation to isolate engineering workstations from production and corporate networks
- Deploy application whitelisting to prevent execution of unauthorized code or malicious project files
🔍 How to Verify
Check if Vulnerable:
Check FvDesigner version by opening the application and navigating to Help > About. If version is 1.5.76 or earlier, the system is vulnerable.Check Version:
No command-line option available. Must check through application GUI.Verify Fix Applied:
After updating, verify the version shows 1.5.77 or later in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Unexpected crashes of FvDesigner.exe
- Unusual process creation from FvDesigner context
- Multiple failed attempts to open project files
Network Indicators:
- Unusual outbound connections from engineering workstations
- File transfers of .fpj files to/from untrusted sources
SIEM Query:
Process Creation where Image contains 'FvDesigner.exe' AND CommandLine contains '.fpj' AND ParentImage not in ('explorer.exe', 'trusted_apps')